The address property of the RTCIceCandidateStats dictionary indicates the address of the ICE candidate. While it's preferred that the address be specified as an IPv4 or IPv6 numeric address, a fully-qualified domain name can be used as well.

When a domain name is specified, the first IP address selected for that address is used, even if the domain name maps to multiple IP addresses.

Either an IPv4 or IPv6 address or a fully-qualified domain name, which corresponds to the candidate.

• If the value of address is comprised entirely of digits from 0-9 with periods as separators, the value is interpreted as an IPv4 address.
• If the value is entirely comprised of hexadecimal digits and colon (":") characters, it is interpreted as an IPv6 address.
• Otherwise, the address is presumed to be a fully-qualified domain name, which is resolved first using an AAAA record (assuming IPv6 is available), then using an A record (if no result is found or the device only supports IPv4). If multiple IP addresses are returned in response to the query, the user agent selects one, which is then used for the duration of ICE processing.

The address property was previously known as ip, and only permitted IPv4 and IPv6 addresses to be used. The addition of support for fully-qualified domain names to be used for the address brought about the renaming of the property.